The present invention is directed to electrical power distribution apparatuses, and especially to electrical power distribution apparatuses that effect distribution from a plurality of power sources to a plurality of electrical conductors using a plurality of electrical bus structures.
Some sites requiring electrical power such as, by way of example and not by way of limitation, telecommunication infrastructure sites require significant power from multiple power system busses. By way of further example, a wireless network cell site may require significant DC (Direct Current) electrical power from a nominal +24V (Volt) bus to power radio equipment and also require significant DC electrical power from a nominal −48V bus to power transmission equipment.
Electrical energy may be delivered from power systems at such sites by means of Power Distribution Apparatuses to receive power from one or more power sources and distribute the received power to a variety of load equipment devices. Power sources may include batteries, AC (Alternating Current) to DC converting power supplies, DC to DC converting power supplies, commercially-provided AC power, AC or DC generators, fuel cells, and other sources of electrical energy. Power is received from the power sources by the Power Distribution Apparatus and is conveyed from the Power Distribution Apparatus to load equipment via electrical conductors, such as electrical busses, as required.
A prior art Power Distribution Apparatus that requires multiple busses (such as the previous example which requires a +24V bus and a −48V bus) is generally configured to provide an independent subsystem for each bus. In the exemplary wireless network cell site referred to above, a Power Distribution Apparatus may include: (1) a +24V power distribution subsystem which receives power from +24V rectifiers (i.e., power supplies that convert commercial AC power to a +24 VDC output signal) and 24V batteries, and distributes the power through overcurrent protective devices such as fuses or circuit breakers to load equipment devices such as radio equipment, and (2) a −48V power distribution subsystem which receives power from 24/48V converters (i.e., power supplies that convert a 24 VDC input signal to a 48 VDC output signal) and distributes the power through overcurrent protective devices such as fuses or circuit breakers to load equipment devices such as transmission equipment.
In most such conventional Power Distribution Apparatuses, the independent subsections or subsystems are fixed and dedicated. In the most common embodiment of the exemplary wireless network cell site referred to above, the Power Distribution Apparatus includes a +24V circuit breaker panel and a separate −48V circuit breaker panel. In another common embodiment of the exemplary wireless network cell site referred to above, the Power Distribution Apparatus includes a circuit breaker panel with some breaker positions configured for +24V operation and other breaker positions configured for −48V operation.
In some prior art Power Distribution Apparatuses subsections within the system can be independently configured between the busses. In a common embodiment of the previous example, two breaker position subsections within a circuit breaker panel can be independently configured for +24V operation or configured for −48V operation.
While the conventionally designed prior art Power Distribution Apparatuses effectively deliver power, there are limitations with such designs. Cost, space utilization, reliability, and required skill level are areas for potential improvement.
In power systems with fixed and dedicated subsystems for each bus, the ratio of space dedicated to each subsystem is fixed so that excess space in one subsection cannot be reallocated to meet the needs of another subsection that requires more space.
Some prior art Power Distribution Apparatuses are configured with sections assigned to each bus. The sections require multiple parts and fasteners so that cost, complexity, and likelihood of error are increased, while reliability is decreased. Further, reassignment of a section to a different bus (if such reassignment is even possible) requires working with tools on equipment amid hazardous energy sites. To avoid working amid hazardous energy sites one may take revenue producing equipment out of service, but this alternative is costly.
There is a need for an apparatus and method for distributing electrical power from a plurality of power sources among a plurality of electrical conductors that requires no fixed ratio of load devices among electrical busses.
There is a need for an apparatus and method for distributing electrical power from a plurality of power sources among a plurality of electrical conductors that has respective device positions that may be individually assigned to a respective bus.
There is a need for an apparatus and method for distributing electrical power from a plurality of power sources among a plurality of electrical conductors that has respective device positions that may be individually assigned to a respective without requiring special skill, high risk, special tools or additional parts or fasteners.